1. Technical Field
The present invention relates to a manufacturing method of a printed circuit board.
2. Description of the Related Art
A printed circuit board is a thin plate to which electrical components such as integrated circuits, resistors, or switches are soldered. The circuit used in most electronic products such as computers are installed on the printed circuit board.
Usually, a printed circuit board is manufactured by laminating a copper foil on a thin substrate made of epoxy resin or bakelite resin which is an insulation, printing an etching resist selectively only on the parts where the copper foil is to remain and form a circuit pattern, selectively etching only the parts where the etching resist is not covered by dipping the printed substrate in an etchant, and then removing the etching resist to form the circuit pattern. As a post-processing procedure, a hole is perforated where an electronic component is to be mounted and solder resist is spread where solder is not to be covered, whereby the manufacturing of the printed circuit board is complete.
As methods of printing a circuit pattern on an insulation substrate, a variety of methods have recently appeared as follows. A first method is the imprinting method, where the pattern formed on a stamper is transferred to a polymer resin by pressing or heat-pressing the stamper, which has a relievo pattern corresponding to the circuit pattern protruding from its surface, onto a polymer resin or liquid monomer and hardening by heat or ultraviolet (UV) rays. However, this method entails the limitation that the circuit pattern has to be formed by plating inside the pattern transferred onto the resin.
A second method is the ink-jet method of printing the required circuit pattern by jetting any of a variety of inks having various ingredients such as polymer, metal, etc., through a nozzle of an ink-jet head, and a third is the stencil method of printing a circuit pattern by ejecting ink through a lattice mesh on which a particular pattern is perforated. However, these methods have the problem that it is hard to form the required thickness of a circuit pattern due to the spreading of the ink, etc.